Various organic materials inclusive of synthetic macromolecular materials such as polyolefin are associated with a problem in that they are subject to oxidation during form-processing and in use to result in degraded quality. To avoid this, various antioxidants have been heretofore developed and added to said materials for the purpose of preventing oxidative degradation.
For example, a hindered phenol compound (e.g., compounds disclosed in Japanese Patent Examined Publication Nos. 17164/1963, 4620/1964, 21140/1964, 9651/1967 and is useful for the prevention of oxidative degradation of synthetic macromolecular materials such as polyolefin in particular, and has been put to practical use.
While 1,1,3-tris-substituted butane compounds have been known as the hindered phenol compounds, for example, UK Patent No. 951935 discloses, as said compound, a compound having phenyl ester structures, which is represented by the formula ##STR3##
U.S. Pat. No. 4,199,495 discloses a compound having ester structures, which is represented by the formula ##STR4##
Japanese Patent Unexamined Publication No. 154851/1977 discloses a compound having ester structures, which is represented by the formula ##STR5##
Japanese Patent Unexamined Publication No. 66551/1977 discloses a phosphite compound of the formula ##STR6## and Japanese Patent Unexamined Publication No. 56239/1978 discloses a phosphite compound of the formula ##STR7## and these compounds have been known as antioxidants for synthetic macromolecular materials.
In addition, as the 1,1,3-tris-substituted butane compound, Japanese Patent Unexamined Publication No. 156152/1987 discloses a flame retardance-imparting compound of the formula ##STR8## and Japanese Patent Unexamined Publication No. 18444/1987 discloses a light resistance-imparting compound of the formula ##STR9##
When a material stabilized with various conventional antioxidants is used in an environment involving water, however, the preventive effect thereof against oxidative degradation becomes markedly poor, and none of the conventional antioxidants has been found satisfactory.
This has been conventionally considered to be attributable to the extraction of the antioxidant with water or the extraction after hydrolysis. Hence, a material to be used in an environment involving water generally contains, for example, an antioxidant devoid of ester structure but having a high molecular weight and rigid structure, such as the composition disclosed in Japanese Patent Unexamined Publication No. 265939/1990, so that the extraction with water or hydrolysis can be prevented.
However, such an antioxidant cannot sufficiently provide resistance to oxidative degradation to a desired degree, and an antioxidant has been desired which effectively prevents oxidative degradation in an environment involving water or hot water.